<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=1, initial-scale=1.0">
    <meta http-equiv="X-UA-Compatible" content="ie=edge">
    <script src="./lib/vue.js"></script>
    <title>简易版计算机</title>
</head>
<body>
    <div id="app">
        <input type="text" v-model="n1">
        <select v-model="opt">
            <option value="+">+</option>
            <option value="-">-</option>
            <option value="*">*</option>
            <option value="/">/</option>
        </select>
        <input type="text" v-model="n2">
        <input type="button" value="=" @click="calc">
        <input type="text" v-model="result">
    </div>
</body>
    <script>
        var vm = new Vue({
            el:'#app',
            data:{
                n1:0,
                n2:0,
                result:0,
                opt:'+'
            },
            methods:{
                calc(){
                    switch(this.opt){
                        case'+':
                        this.result=parseInt(this.n1)+parseInt(this.n2)
                        break;
                        case'-':
                        this.result=parseInt(this.n1)-parseInt(this.n2)
                        break;
                        case'*':
                        this.result=parseInt(this.n1)*parseInt(this.n2)
                        break;
                        case'/':
                        this.result=parseInt(this.n1)/parseInt(this.n2)
                        break;
                    }
                    var codeStr='parseInt(this.n1)'+this.opt+'parseInt(this.n2)'
                    this.result=eval(codeStr)
                }
            }
        });
    </script>
</html>